Stereoselective Synthesis of (Z)‐ and (E)‐Allyl Aryl Sulfides and Selenides from Baylis?Hillman Acetates under Neutral Conditions Using β‐Cyclodextrin in Water

The first example of the stereoselective synthesis of (Z)‐ and (E)‐allyl aryl sulfides and selenides from Baylis? Hillman acetates under neutral conditions in H₂O by supramolecular catalysis involving β‐cyclodextrin is reported. β‐Cyclodextrin can be recovered and reused. The reaction is very efficient in providing allyl aryl sulfides and selenides in good‐to‐excellent yields with clean reaction profiles under mild reaction conditions.     

A review of transition metal chalcogenide/graphene nanocomposites for energy storage and conversion

Recent advances in the applications of transition metal chalcogenides/graphene (TMC/graphene) nanocomposites in future energy storage and conversion are reviewed. The synthesis processes and structures of TMC/graphene, workingpriciple of evergy energy device, and the electrochemical performances are summarized.     

Application of organic selenides and tellurides in organic synthesis

This paper describes the progress on the synthesis of organic selenides and tellurides and their application in organic synthesis.Low valent selenium and telluronium compounds having high reducing selectivity can be used to form carbon-hydrogen bonds as special reducing reagents.Telluronium ylides can react with aldehydes and ketones by Wittig-type condensation to produce (E)-configuration alkenes stereoselectively.α-Phenylselanyl arsonium ylides were prepared by transyl-idation reaction of arsonium ylides with phenylselanyl halides which can undergo Wittig-type reactions with carbonyl compounds to give (Z)-α-selanyl-α,β-unsaturated compounds with high stereoselectiv-ity.Zirconium,tin,boron,halogen,metal or hetero-atom were introduced in organoselenium and telluronium compounds as new difunctional group reagents.Under transition metal catalysis,the corresponding cross coupling reactions provide new methods of formation of carbon-carbon double bonds,which were used in the stereoselective synthesis of     

Stereoselective Z-iodoalkoxylation of 1,2-allenyl sulfides or selenides

Iodoalkylation of 1,2-allenyl sulfides or selenides with I₂ in MeCN/ROH (20:1) afforded Z-3-alkoxy-2-iodopropenyl sulfides or selenides in high stereoselectivity and moderate to good yields. The carbon-iodine bonds in these compounds may undergo Suzuki, Negishi, and Sonogashira coupling reaction smoothly.     

Darstellung und Kristallstruktur von SnTl4Se3 mit einer Anmerkung zu TlSe

Preparation and Crystal Structure of SnTl₄Se₃ with a Note on TlSe We describe the preparation and crystal structure of SnTl₄Se₃. It crystallizes as a low symmetric distorted derivative with the In₅Bi₃ type of structure, which itself should be considered as a subfamily of the Cr₅B₃ type of structure: a = 852.2(2) pm, c = 1 272.2(6) pm, c/a = 1.49, Z = 4. Short Sn? Se distances of 311 pm, and 326 pm, respectively, are obtained in [SnSe_2/2] chains running along [001]. Furthermore, short Tl? Se distances are found in quasimolecular bent moieties Tl₂Se: 300 pm, 313 pm, and 347 pm, respectively. SnTl₄Se₃ is a semiconductor. The conductivity of some closely related phases are also reported. Finally, the structure of the well known compound TlSe has been refined for the first time, in order to get some more information about Tl¹⁺? Se distances for square-antiprismatic coordinated Tl¹⁺ ions.     

An indium-TMSCl promoted reaction of diphenyl diselenides and aldehydes: novel routes to selenoacetals and alkyl phenyl selenides

The reaction of diphenyl diselenides with aldehydes in the presence of In-TMSCl has been investigated. Aliphatic aldehydes provide the corresponding selenoacetals, whereas aromatic aldehydes lead predominantly to alkyl phenyl selenides under the same reaction conditions. This constitutes a new approach for the synthesis of selenoacetals and selenides from aldehydes.     

Zr7(Sb,Se)4 – eine polare Variante des Nb7P4-Strukturtyps

Zr₇(Sb,Se)₄ – a Polar Variant of the Nb₇P₄ Structure Type Single crystals of Zr₇Sb_1.6(1)Se_2,4 were obtained by arc-melting of compressed mixtures of Zr, ZrSb₂, and ZrSe₂, followed by annealing at 1300 °C in an induction furnace using traces of iodine to promote crystal growth. The crystal structure (a = 375.98(4), b = 1662.6(2), c = 1476.7(2) pm, V = 923.1(2) 10⁶ pm³, Cmc2₁, Z = 4) was determined by single crystal X-ray means. Zr₇Sb_1.6(1)Se_2.4 forms a unique polar structure composed of condensed tri-capped trigonal prismatic Zr₉ clusters, being stabilized by interstitial Sb/Se atoms. The remaining Sb and Se atoms reside in mono- and bi-capped trigonal prismatic Zr₇ and Zr₈ clusters, respectively, of the extended cluster network. Characteristic structural distinctions and relations between Zr₇(Sb,Se)₄ and congeneric Zr₇P₄ are highlighted.     

Probing the Metal Composition of Ternary 12–12′‐16 Nanoclusters via Electrospray Ionization Mass Spectrometry

The reaction of [(3,5‐Me₂–C₅H₃N)₂Zn(SeSiMe₃)₂] with a solution of Cd(OAc)₂, Se(Ph)SiMe₃ and PPr₃ at low temperature was used to prepare single crystals of ternary group 12–12′‐16 nanoclusters with the composition [Zn_1.8Cd_8.2Se₄(SePh)₁₂(PPr₃)₄]. A ligand exchange reaction using Na[SePh] was performed to displace the neutral PPr₃ ligands. The resulting clusters were probed using electrospray ionization mass spectrometry to determine the number of zinc and cadmium atoms in the cluster and compared to the all cadmium cluster [Cd₁₀Se₄(SePh)₁₂(PPr₃)₄]. The dianionic clusters [Zn_xCd_10–xSe₄(SePh)₁₄]^2– where x = 0, 1, 2 were assigned in the mass spectra, revealing that the clusters exhibit elemental distributions that are quite narrow in these experiments.     

Zr2N2Se: The First Zirconium(IV) Nitride Selenide by the Oxidation of Zirconium(III) Nitride with Selenium

The oxidation of zirconium(III) nitride (ZrN) with suitable amounts of selenium (Se) in the presence of sodium chloride (NaCl) as flux yields small yellow brownish platelets of the first zirconium(IV) nitride selenide with the composition Zr₂N₂Se. The new compound crystallizes in the hexagonal space group P6₃/mmc (no. 194) with a = 363.98(2) pm, c = 1316.41(9) pm (c/a = 3.617) and two formula units per unit cell. The crystallographically unique Zr⁴⁺ cations are surrounded by three selenide and four nitride anions in the shape of a capped trigonal antiprism. The Se^2– anions are coordinated by six Zr⁴⁺ cations as trigonal prism and the N^3– anions reside in tetrahedral surrounding of Zr⁴⁺ cations. These [NZr₄]¹³⁺ tetrahedra become interconnected via three edges each to form $\rm^{2}_{\infty}$ {[(NZr_4/4)₂]²⁺} double layers parallel to the (001) plane, which are held together by monolayers of Se^2– anions.     

An indium-TMSCl promoted reaction of diphenyl diselenide and diorganyl disulfides with aldehydes: novel routes to selenoacetals, thioacetals and alkyl phenyl selenides

The reactions of diphenyl diselenide and dialkyl disulfides with aldehydes in the presence of In-TMSCl have been investigated. Aliphatic aldehydes provide the corresponding selenoacetals and aromatic aldehydes lead predominantly to benzyl phenyl selenides on reaction with diphenyl diselenide. However, the reaction of dimethyl disulfide and diphenyl disulfide with both aromatic and aliphatic aldehydes produce dithioacetals. This provides a novel route to the synthesis of selenoacetals, thioacetals and selenides from aldehydes.